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authorHugh Dickins <hughd@google.com>2021-06-24 18:39:07 -0700
committerSasha Levin <sashal@kernel.org>2021-06-30 08:47:28 -0400
commit7b55a4bcfccf839d5b65fbfba82f8edcf1bef423 (patch)
tree3f4609021e2568a940714c64d5895581ff922fb8 /mm
parent1cb0b9059f9ef46e113fd90ed50accbc877cc013 (diff)
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mm: page_vma_mapped_walk(): use pmde for *pvmw->pmd
commit 3306d3119ceacc43ea8b141a73e21fea68eec30c upstream. page_vma_mapped_walk() cleanup: re-evaluate pmde after taking lock, then use it in subsequent tests, instead of repeatedly dereferencing pointer. Link: https://lkml.kernel.org/r/53fbc9d-891e-46b2-cb4b-468c3b19238e@google.com Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Peter Xu <peterx@redhat.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: Wang Yugui <wangyugui@e16-tech.com> Cc: Will Deacon <will@kernel.org> Cc: Yang Shi <shy828301@gmail.com> Cc: Zi Yan <ziy@nvidia.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/page_vma_mapped.c11
1 files changed, 6 insertions, 5 deletions
diff --git a/mm/page_vma_mapped.c b/mm/page_vma_mapped.c
index 4f04472effb7..821147eca0e1 100644
--- a/mm/page_vma_mapped.c
+++ b/mm/page_vma_mapped.c
@@ -190,18 +190,19 @@ restart:
pmde = READ_ONCE(*pvmw->pmd);
if (pmd_trans_huge(pmde) || is_pmd_migration_entry(pmde)) {
pvmw->ptl = pmd_lock(mm, pvmw->pmd);
- if (likely(pmd_trans_huge(*pvmw->pmd))) {
+ pmde = *pvmw->pmd;
+ if (likely(pmd_trans_huge(pmde))) {
if (pvmw->flags & PVMW_MIGRATION)
return not_found(pvmw);
- if (pmd_page(*pvmw->pmd) != page)
+ if (pmd_page(pmde) != page)
return not_found(pvmw);
return true;
- } else if (!pmd_present(*pvmw->pmd)) {
+ } else if (!pmd_present(pmde)) {
if (thp_migration_supported()) {
if (!(pvmw->flags & PVMW_MIGRATION))
return not_found(pvmw);
- if (is_migration_entry(pmd_to_swp_entry(*pvmw->pmd))) {
- swp_entry_t entry = pmd_to_swp_entry(*pvmw->pmd);
+ if (is_migration_entry(pmd_to_swp_entry(pmde))) {
+ swp_entry_t entry = pmd_to_swp_entry(pmde);
if (migration_entry_to_page(entry) != page)
return not_found(pvmw);